Test machine to apply a uniform internal pressure to a tube

Abstract

This machine comprises a central body ( 1 ), un piston ( 3 ) compressing the liquid contained in a liner ( 2 ), and a peripheral bladder ( 18 ) capable of uniformly applying pressure to a tube ( 21 ) immediately surrounding this bladder. Pressure can be applied in a simple manner through a tensile and compression testing machine ( 22, 23 ). No end effect that could disturb the test is produced on the tube.

1. Test machine to apply a uniform internal pressure to a tube ( 21 ), comprising a body ( 1 ), a piston ( 3 ) sliding in the body and varying a volume of a liner ( 2 ) contained in the body ( 1 ), an annular elastic bladder ( 18 ) surrounding a periphery of the body, the periphery of the body comprising two circular ribs ( 12 ,  13 ) and a recess ( 14 ) separating the ribs and communicating with the liner ( 2 ), the machine also comprising two flanges ( 6 ,  7 ) fixed to the body at two opposite ends and comprising annular mating flanges ( 9 ,  10 ) surrounding the ribs ( 12 ,  13 ) respectively, the bladder ( 18 ) being clamped at each of the two opposite ends between one of the ribs and one of the mating flanges. 
     
     
       2. Test machine according to  claim 1 , characterised in that mating flanges are fixed to flanges through means ( 11 ,  5 ) for adjusting the distance between mating flanges. 
     
     
       3. Test machine according to  claim 2 , characterised in that means ( 11 ,  5 ) for adjusting the distance between mating flanges comprise attachment screws and distance adjustment screws. 
     
     
       4. Test machine according to any one of  claims 1  to  3 , characterised in that it is associated with a tensile and compression testing machine, on plates ( 22 ,  23 ) of which the piston ( 3 ) and one of the flanges ( 7 ) are installed respectively.